Guidelines on Designing MicroRNA Sponges: From Construction to Stable Cell Line

Multifaceted role of microRNA-301a in human cancer: from biomarker potential to therapeutic targeting

With the growing data on microRNA (miRNA) expression in tissues and circulation, there is increasing evidence for the potential of microRNAs to serve as biomarkers in cancer diagnosis and prognosis, as well as novel therapeutic targets. The expression level of miRNA-301a (miR-301a) is altered in a wide range of human tumor types, and numerous studies have revealed the roles of miR-301a in tumorigenesis and tumor progression. Herein, we comprehensively summarize, compare, and contrast the research advancements on the role of miR-301a in different cancers. Differential expression patterns of miR-301a in tissues and biofluids are implicated in cancer diagnosis, treatment response, and prognosis. MiR-301a modulates the expression of multiple genes, other noncoding RNAs, and signaling cascade via direct or indirect regulation in human cancer proliferation, migration, invasion, angiogenesis, and radio- or chemotherapy resistance. Cancer cell-associated miR-301a affects the tumor microenvironment through the alteration of immune function and cancer metabolism. These findings highlight the functional roles, clinical implications, and therapeutic relevance of miR-301a in various human cancers.

Emerging roles and mechanisms of microRNA‑222‑3p in human cancer (Review)

MicroRNAs (miRNAs/miRs) are a class of small non‑coding RNAs that maintain the precise balance of various physiological processes through regulating the function of target mRNAs. Dysregulation of miRNAs is closely associated with various types of human cancer. miR‑222‑3p is considered a canonical factor affecting the expression and signal transduction of multiple genes involved in tumor occurrence and progression. miR‑222‑3p in human biofluids, such as urine and plasma, may be a potential biomarker for the early diagnosis of tumors. In addition, miR‑222‑3p acts as a prognostic factor for the survival of patients with cancer. The present review first summarizes and discusses the role of miR‑222‑3p as a biomarker for diverse types of cancers, and then focuses on its essential roles in tumorigenesis, progression, metastasis and chemoresistance. Finally, the current understanding of the regulatory mechanisms of miR‑222‑3p at the molecular level are summarized. Overall, the current evidence highlights the crucial role of miR‑222‑3p in cancer diagnosis, prognosis and treatment.

microRNA-23a in Human Cancer: Its Roles, Mechanisms and Therapeutic Relevance

microRNA-23a (miR-23a) is one of the most extensively studied miRNAs in different types of human cancer, and plays various roles in the initiation, progression, and treatment of tumors. Here, we comprehensively summarize and discuss the recent findings about the role of miR-23a in cancer. The differential expression of tissue miR-23a was reported, potentially indicating cancer stages, angiogenesis, and metastasis. miR-23a in human biofluid, such as plasma and salivary fluid, may be a sensitive and specific marker for early diagnosis of cancer. Tissue and circulating miR-23a serves as a prognostic factor for cancer patient survival, as well as a predictive factor for response to anti-tumor treatment. The direct and indirect regulation of miR-23a on multiple gene expression and signaling transduction mediates carcinogenesis, tumor proliferation, survival, cell migration and invasion, as well as the response to anti-tumor treatment. Tumor cell-derived miR-23a regulates the microenvironment of human cancer through manipulating both immune function and tumor vascular development. Several transcriptional and epigenetic factors may contribute to the dysregulation of miR-23a in cancer. This evidence highlights the essential role of miR-23a in the application of cancer diagnosis, prognosis, and treatment.

Use of a Recombinant Mosquito Densovirus As a Gene Delivery Vector for the Functional Analysis of Genes in Mosquito Larvae

In vivo microinjection is the most commonly used gene transfer technique for analyzing the gene functions in individual mosquitoes. However, this method requires a more technically demanding operation and involves complicated procedures, especially when used in larvae due to their small size, relatively thin and fragile cuticle, and high mortality, which limit its application. In contrast, viral vectors for gene delivery have been developed to surmount extracellular and intracellular barriers. These systems have the advantages of easy manipulation, high gene transduction efficiency, long-term maintenance of gene expression, and the ability to produce persistent effects in vivo. Mosquito densoviruses (MDVs) are mosquito-specific, small single-stranded DNA viruses that can effectively deliver foreign nucleic acids into mosquito cells; however, the replacement or insertion of foreign genes to create recombinant viruses typically causes a loss of packaging and/or replication abilities, which is a barrier to the development of these viruses as delivery vectors. Herein, we report using an artificial intronic small-RNA expression strategy to develop a non-defective recombinant Aedes aegypti densovirus (AaeDV) in vivo delivery system. Detailed procedures for the construction, packaging and quantitative analysis of the rAaeDV vectors, and for larval infection are described. This study demonstrates, for the first time, the feasibility of developing a non-defective recombinant MDV micro RNA (miRNA) expression system, and thus providing a powerful tool for the functional analysis of genes in mosquito and establishing a basis for the application of viral paratransgenesis for controlling mosquito-borne diseases. We demonstrated that Aedes albopictus 1^st instar larvae could be easily and effectively infected by introducing the virus into the water body of the larvae breeding site and that the developed rAaeDVs could be used to overexpress or knock down the expression of a specific target gene in larvae, providing a tool for the functional analysis of mosquito genes.